Apparatus and method for the control of air flow through furnace tuyeres



March 16, 1943. H, A REECE 2,313,769

APPARATUS AND METHOD FOR THE CONTROL OF AIR FLOW THROUGH FURNAOE TUYFRES' Filed DEC. 17, 1941 5 Sheets-Sheet l v "mlm M n I 11"' 'l INVENTOR 44 IgM-nulli 4a; 4s BY SZ. v1'

ATTORNEYS.

March 16, 1943. H. A, REECE 2,313,769

v APPARATUS AND METHOD FOR THE CONT L OF AIR FL OUGH FURNACE TUYE s F' ec. 17, 1941 3 Sheets-Sheet 2 I HEemIAEEn-E.

` i I 'INVENTOR ATIDBNEY?.

` Marchle, 1943. H A REECE 2,313,769

APPARATUS AND'ME'THOD FOR THE CONTROL OF A IR FLOW THROUGH FURNACE TUYERES Filed Deo. 17, 1941 3 Sheets-Sheet 3 I N VEN TOR. HwmARw BY fs/ZIM# ATTORNEYS .the relative vvelocities of an air Patented Mer. is, 1943' ),uNlTEo-sTAT Es PATENT OFFICE APPARATUS AND METHOD Fon 'rua coN- raor. or? Am now Tnaovcn FUnNAoE -'rUitEitEs Herbert A. Reece, Cleveland Heights, Ohio Application neeembell '17, 1941, serai No. 423,334 zo claims. (ci. 26a-ao) My invention relates to supply apparatusfor delivery `of air and the like to furnaces such as metallurgical furnaces and thelike andrto operation of the same. y Y s` My present invention, herein described,`is related in subject matterl to my invention described in my United States Letters Patent No. 2,197,947

issued lApril 23, 1940, and is directed to the same and similar problems of furnaceloperation`and control of air flow as is set forth in said patent andto other problems of furnace operation.

In the following discussion and description the operationand structure of a cupola for the remelting or metal will be referred to but 1t is to l' be understood that my invention includes the structure and operation of all furnaces or similar devices wherein a blast of. air or other gases ls supplied through a plurality of tuyres or like openings to the interiorof the furnace or similar Itis an object of my invention to` provide improved apparatus for supplying an air blast through a plurality of tuyres-to theintrerior of .a furnace.

Another object is the control of the airblast delivered to a furnace lthrough a plurality of l Another object is the modification of the cur- A rent of air entering the plurality of tuyres of a tuyres in order to meet varying conditions and requirements.

Another object is the provision for adjustment yof the modification of the flow of plurality of furnace tuyres.

Another object is the provision for supplying air through va plurality of tuyres at velocities and in amounts in accordance with conditions j I and requirement s.` l i Another object is'the provision for directing the flow of air through furnace tuyres as required.. f

Another object is the provision for Vmodifying' Athe direction of the flow of air into a furnace from a tuyre. l Another object is the provision forvarying the character' of the flow of air through a-plurality of tuyres into a' furnace.

.Another object is the provision of yiemabie resistors at each of a plurality of tuyreseand adjustable means for positioning the resistors in l the tuyres as required.

- Another object is the provision for controlling and directing the flow f air through the tuyres of a-fumace to feed the air to the 'interior of the furnace as desired. A f

`Another object is the provision of yieldable resistors and adjustable means for changing the position of the resistors relative tothe tuyres sistance to the flow ofair through the tuyres 4o of a furnace to control the through the tuyres.

velocityof the airl Another object is the-provision for modiilcaf. tion of `the: velocity of an air blastgthrough a tuyre by resistance to the air blast which yields '45 to the force of the air blast. i

l Another object is the provision for adjusting blast passing through a plurality of tuyres. f

Another object isthe provision of apparatus and method by means of which the velocities of air blastethrough a plurality of .furnace tuyres may be equalized.

Another object is the provision for flexible control of the. flow of air through a plurality of f member with the vane to 4provide access to the tuyres. A

Another object is' the provision of apparatus for the carrying out of the foregoing objects.

Another object is the provision of a method for the attainment of the stated desired result.

Other objects anda fuller understanding of myrinvention may be had by referring to the following descriptionand claims, taken in conjunction with the accompanying drawings, in which: t l

Figure l is a cross-sectional view through half of a cupola and wind box incorporating my inf vention and is an enlargement of a view throughthe line i--I of Figure 2; l Y -Figure y2 is across-sectional Vview .taken lengthwise of a cupola and wind box incorporating my 4 invention; l

'i Figure 3 is a fragmentary detail view of my apparatus through the line 3 3 of Figure l; "i

Figure 4 is'a fragmentary detail view of one of my-vane ,members at a tuyre and illustrates'the 'mounting of the vanemember to the cupola Figure illustrates a modified form of vane tion:

.LFigure B illustrates the vanemember of Figure air through a I plates tilted in one direc- .vane member;

2 l l. l

5 with the vane plates tilted in another direcftion;

Figure '7 illustrates 'another modied form' of Figure 8 is a viewl of an end plate of member shown in Figures' and 6, looking in the direction of the arrows 8--8 of Figure 5;

Figure 9 is a cross-sectionalview through half of a cupola and wind box somewhat similarto the view of Figure 1l and illustrates another ar` rangement of parts incorporating my invention, wherein the vane members may be adjustably moved forward and/ backward through the Figure 10 is a fragmentary enlarged view of my apparatus taken throughthe line ill- I0 of Figure-9;

Figure 11 is a fragmentary detail view of one f of the vane members or the modified arrangement of Figures 9A and 10 and illustrates the mounting of the vane member to the cupola'at atuyre;

` upon the cupola body 2| bykveiding or other-.suitable meansand in the embodiment shown, the

outer wall of the cupola body forms one of the enclosingwallsof the wind box 2 2'. It is there- 'fore seen from the viewsy of the drawings .that

the wind box -22 forms an enclosed jacket vsurrounding the Icupola body 2i in such a way that air introduced into -the windbox may circulate entirely around the cupola body'. i

The inlet conduit nis in communication with the air blower or other source o f an air blast- .y (not' shown) and ithe inlet cond-uit 23 is connected to the wind box 22 at the upper portion Figure 12 is an enlarged fragmentary and sectional View illustrating theladjustable mounting 'of a vane member in the modified arrangementl of Figures 9 land 10;

-Figure 13 illustrates a modication in the form the form of vane member which may beutilized v in the practice of my invention;

. Figure l5 illustrates still another modification in the form o f vane member which maybe utilized in the practice of my invention;

Figure 16 is a cross-sectional. View through halfv illustrated in Figures 1, 2, 9, 16 and 17, and the other three tuyres of the other half ofcthe fur` of vane member which may be `utilized in the y practice ofmy invention; i y Figure 14 illustrates another modification in'- of a cupola and wind box somewhat similar to the views of Figures 1 and 9 and illustrates an'- other arrangement of parts. incorporating my invention, wherein thevane members may be moved up and down relativevto the tuyres and in dierent positions in the respective bootleg pipes connecting each tuyre with the wind box;-the view of Figure 16 being taken through the line i 6|6 of Figure 17;

Figure 17 is a sectional view taken lengthwise 1 .and therefore the drawings do notinclde the top portion and the bottom portion of the cupola, which portions may be considered as having the usual form. Also, for purposes of simplicity inv illustration, the usual tap hole and slag hole are out door, breast arch, or drop-bottom doors.

The cupola with". which 'the invention is associated andwhich isdescrlbed herein may be considered, however. as'having .all ofthe parts necessary for the usual operation o! the same;

Vlis shown in the several views of the drawings thercupola body or shell 2| is in' ,the form of a cylindrical shaft, .the inner walls oi the cupola body 2| being lined .by the rire brick lining 24.'-

:noemer 2i andi-,he lining 2| are mounted upon the usu'aottomfpieteand 'thereby forming the enclosed shaft of 'the cupola.;

A wind pox zz or cylindrical shape is mounted around of the wind box 22 so as to aiord communication between the air blowerand theV inlet opening 25 of the wind box 22. i

In the cupola 4illustrated there are six tuyres extending through the wall and lining of the cupola body M to 'establish communication betweenthe interior of vthe shaft of the cupola and 5 the wind box 22, 'lluyres 30, 3i and 32;y as seen from the inside of the shaft ofthe cupola are nace are similar. These six tuyres are of'substantially equal size and are uniformly` spaced a low level in the cupola `andcommunicate with the wind box in a llower portion thereof.

of my inven- The description of the iirstforn tion for controlling the flow of air blast through the Iplurality of tuyres of a furnace is made in conjunctionwith the showing of1igures 1 to 8,'

inclusive. With reference to said figures there is shown positioned at the entrancefof each of the tuyres, from the side \of thewind box, va

' `lplurality of vane members denoted generally 'by the reference character 2S. vEach vane member 2S is in the form of a paddle-wheel or fan composed of a plurality of bladesll disposed radially of a common axis. The' opposite ends of' the blades Adare welded or otherwi e secured to disk end plates 39 to form the assembled vanemember 26.- A shaft 29 extends through. and is welded or otherwise rigidly secured to, the disk end plates 39 in such manner that the vane `members 2t revolve with. the respective shafts 29." The individual vane plates du do notextend inwardly to meet at the shaft 29 but arespaced radially therefrom to permit some leakage of air-.through the axial center of the vane member without being blocked or resisted.

A vane member 26 (six ofthem in number) is positioned at each of the six tuyres of the furnace so "as to dominate and control the flow ofair through the respective tuyre.- Bearing supports 21 and 2B for mounting the vane members 26 in'position are secured by bolts fil or by other `not shown. vIt has also been considered unneces- Y sary to illustrate such 'other openings as a cleansuitable means to the cupola shell 2i adjacent the sides c! the tuyres, The extending ends of each shaft!! are supported by the bearing supports 21 and 2l in such manner that the shaft 2010i each vane member 26) is rotatabile rela#- tive to the respective bearing supports 21 .and

28; -The axes of the vane members, thatA is, the1 shafts 29.V are" disposed-horizontally in the furnace and are positioned about mid-way between thel top and bottom walls of the respective tuyres. e

The bearing supports 21 and 2s both' have openings whieh'accommodate the shaft 29- and permit the'shaft to rotatetherein.- The bear-y ing support 23 diilers from the' bearing support 21 in that it has auotheropening extending the periphery of the cupola. It is to be noted that. the tuyres enter the cupola body at.

through a side thereof. An adjusting rod 36 having a 'threaded end 31 extends'across the wind box from each bearing support 28 andA through a hermetically sealed opening in the wall of the wind box.

threaded end.31 of therod 3.6. The inner end face of therod e36 is adapted to engage the annular surface ofthe shaft 29 and to frictionally retardthe rotation of the shaft. The engagement of the inner end face of the rod 36 against the shaft 29. The frictional `engagementof the rod. on the shaft 29 therefore forms resisting 'and yielding meansl permitting the vane members to revolve and at the same time governing l, turned to apply the desired amount of pressure against, and frictional engagement with, one of the shafts 29. In thismanner thel desireddegree of retardation of the revolving 'of each vane member 26 may be nicely obtained. The rate of revolving of each of the six vane members 26 under the force of the air blast may be independently adjusted by adjustablyy retarding the revolving of 'each vane memberI through varying 3 6 and shafts-29.

In air supply apparatusfor cupolas-and the likehaving no means in the wind box yfor equalizing the flow of air' before reaching the plurality of tuyres, the air may flow through different tuyres at unequal rates.

In the absence of means in the wind boxfor obtaining equalized The bearingsupport 29 is f internally threaded to threadably receive the asians of the furnace operation.

` the arcuate surface of the'shaft 29 is -such that 1 4the rod 36 yields to the force which may turn shows one of the end plates 43v and the radialA th'e frictional engagement of the respective rods l velocities in the plurality of tuyres, as shown for example in my previously issued patents, the air .currents in the-wind box' 2'2 supplied from the blast main 23 may be of such a character that the air flowing through one tuyre may travel at an excessive rate while at the same time the air flowing throughanother tuyre may travel at an insufficient rate. The inequality in the velocity.

of air flowing through the .several tuyres is a disadvantage in the efficient operation of the furnace 'and adversely -ailects the melting operation therein.

The vane members 26 being inthe path of the flow of air through each ofthe tuyres resists the'ilow. As the vane members may rotate under the force of the air blast they yield thereto and permit the air to 'continue to flow. 'I'he vane members may therefore be termed yieldable resistors. The degree ofyieldance of the vane members to the force of the air blast affects the rate oi flow of air passed by the vane members. The yieldance is adjusted by turning the handles 39to vary the retardation of revolving of the vaneV members 26. In' tuyres wherein the flow of 4air blast tends to become excessive the tuyres.-and the flow of air through the tuyres i into the furnace is equalized. The plurality of yicldable resistors at' the .tuyres thus provide.

means for equalizingthe velocity of the air blast through the plurality of tuyres. 'The system il disk end plates 43.

In Figures 5, 6 and s' merels illustrated a slightly modified form of vane member that may be utilized in my apparatus. Inthis modified .form ofvane member., individual vane plates 46 are assembled around the shaft .29 by means of 'I'he opposite end plates. have radially disposed slots 41 into which the ends of the plates 46 extend. Collars 44 ywelded or otherwise secured to the respective end plates 43 receive the shaft 29. A set-screw 4 5 threadably engaged in the collar 44 engages the side of the shaft 29 and thus holds the assembled plates 46" and end plates 43 in fixed rigidpositlon to revolve with the shaft 29.' By adjusting the-position .of the collars 44 onthe shaft 29 the plates 46 may be secured in one tilted position or another or securedin straight position. Figure 5 shows the assembly with the vblades tilted in one direction and Figure 6 shows the assemblywith the`blades tilted in another direction. Figure 8 slots 41 for receiving theends of the plates 46.

' It is sometimes desirable to shift the flow of air through the tuyre from ,one side to the other.- 'I'he air blast is sometimes of a swirling or deflected nature and unless corrected passes through the tuyre into .the furnace in an unsatlsfactory manner. At other times it is desired to purposely pass the air blast toward one side or another as it goes through thev tuyres. form of vane member shown in Figures 5 and 6 provides a convenient and flexible means of modifying the nature of the flow of air through a tuyre.

Figure 7 shows a vane member somewhat similar to that shown-in Figures 5 and 6. In Figure 7, individual vane plates 49 and individual vane plates 50 extend about half the length of the assembled vane member and have their adjacent ends carried by a middle slotted plate 48', the

other ends 'beingcarried by the slotted end plates 43. By shifting theposition of the plates 5 0 and securing them in the shifted position to the shaft 29, a vane member of desired structure may be obtained. By way of example, Figure 7 illustrates one position in which such a vane member may be secured. The direction of the air blast through a tuyre may be modiiledby the vane member of Figure 7, as in the case of the vane to neutralize the tangential flow of air in the wind box to any degree desirable.

A modified arrangement of parts in my apparatus is illustrated in Figuers 9 to l2, inclusive. In this modified arrangement, the position of the revolvable vane members or `resistors in the tuyres may be adjustably fixed as required. In the modified arrangement of -Figures 9 to 12, the

vrevolvable vane members are denoted generally by the reference characters 62. Each vane member 52 is made up of an assembly of vane plates 64 rigidly mounted upon a shaft .63 so asv to revolve with the shaft. Ihe'vane plates are somewhat arcuate torevolve more freely and positively under the force'of theair blast, as is illustrated in the view of Figure 10.

To provide means for mounting the vane members 52 in the respective x tuyres, vertical'steel plates 55 are positioned onfltheopposite vertical sides of each tuyre. Each plate l5 has a horizontally disposed slot l66about mld-way between the topand bottom of the tuyre. The ends of The i ures 10 and 11. In each tuyre, having a pair welded to the flanged portion 6| or otherwise se- .horizontal position through the flanged portion tion '9| and `across the wind box and through the wall thereof, as shown in Figures 9 and 10.

. means of sliding support member 59 and threadby the support portion i.'

sist the flow 4 a manner that the shaft 53 lmay move orward gud backward in the tuyre in a horizontal direcion. I The outer edge .portion of each vertical plate 5 55 adjacent the wind b'ox is bent at right angles to form the hanged portion 9|, as shown in4 Figof plates 55 therein, meansare provided for moving the vane members 52 forward and backward. 10

Along one side of each tuyre a slide rod '51 ex4` tends in ahorizontal directipnfrom the flanged portion 6I and between the plate 55 and the side wall of the tuyre and has its forward or inner end covered or protected by the fire-brick lining 24 ofthe cupola. The outer end ofthe rod 51 is cured in fixed position. Along the opposite side of each tuyre a threaded rod -58 extends. in a 6I and between the side wall of the tuyre .and has its forward end vcoviered or protected by the fire brick'lining 24 of the cupola. The rod 59 extends through an opening in the flanged por- An abutting flange 68 on the rod 58 slidably engages the inner wall of the wind box 22 and any abutting flange 69 slidably engages the face of the flanged portion 6i of the plate 55. In this way the rod 58 is permitted to rotate on its own axis but is held against longitudinal movement. There is a .hermetic seal between the rod 58 :and the outer wall of the wind box, the seal per mittingthe rod 58 to turn upon the revolving of the crankhandle on the outer end of the rod outside of the wind box. y

l'I'hejshai't 53 is connected to, and carried by, the slide rod 51 and the threaded rod 59, vby

d support member ySi), respectively. -The slide support member'l slides on the rod 51 and the threaded support member 601g, moves back and forth on rod 58 upon the turning of rodi 5i). Figure 12 illustrates the mounting of member 60 on ioclv 58. The' mounting ofmember 59 on rod 51 is similar except that there is a sliding engagneit between them rather than a threaded engagement. g

-'l'lie ends of the shaft 53 are rotatably carried members 59 and 80, as illustrated in Figure 12. The shaft 53 and the vane member 52 are revolvable relative to the support members 59 and. To provide yieldable means for adjustably retarding the revolving of the vane member, a threaded adjusting bolt 62 extending through the support member 62 resilently presses a ball bearing. by means of a coil spring 63 against theside of the shaft 53. The frictional engagement of the ball 64 and shaft ,53 may be finely adjusted by turning the bolt s2. Aeshown in Figure 11, thebolt 62 may be reached by a suitable wrench through an opening in the anged The mechanismdescribed for moving a vane 35 member 52 backward and forward is the saine for `each vane member at the respective tuyres. It is seen that by turning the crank handles on the rods 59v the respective vane members 52 ymay be moved" backward and' forward in the tuyres. The vane ymembers 52 revolve under the force of the air blastthrough the tuyres `and are retarded in their revolutions by the adjustable retarding means described. The vane members re,

` of air'through the tuyre and, upon 7g;

. now ,ofv air at a tuyre' may asisfroo l h revolving yield'to the force or the flow of ali'.

'I'he frictional retarding means yields to theforce revolving the vane members and provide adiusti able yielding means controlling the revolving of the vane members. .By governing 'the revolving of the vane members the iiow of air through the tuyresi s controlled vand 'z xiodined.l Excessive Y be corrected by' 'ad-` Justably applying greater' resistancel to the revolving of the vane'lnemberv at 'that tuyre to hold back the iiow of air. f

The directional flow of air through the tuyres:

`may be modifiedJ by substituting vane'mernbers such as shownin Figures 5, 6 Aand '1in-.thc apparatus of Figures 9L to 11. Thefiow-ofgairis l.

directed into the interior of the' furnaceY in"l ai manner to-meet particular operatingv conditionsA and requirements.

Greater flexibility to the control-of air through the' tuyres is obtained by adjusting the position of the vane members in therespective'tuyres. A1so,.the control of .thev direction of the yblast of' air from the tuyre into ,the interior of the furnace may be obtained to a considerable extent by changing the position of the vane member inthe tuyre. The flow of air may be' diil'used, concentrated or otherwise modified by rnoving the vane member to dierent positions in the tuyre relative to the'interior of the cupola.

In. the apparatus illustratedin Figures 9, l0 and 11 the vane member 52 has arcuate shaped vane plates 5l as shown in Figure 10,. Modified forms of vane members shown in Figures 13; 14

and 15 may be 'used in the place of the vane ,member 52. In Figure I3,y the vane mem-ber has arcuate shaped blades which extend into the shaft 59 to form a closed center, the blades l5 curvinginone direction. Figure 14 shows avane member similar to that shown in' Figure 13 .except that the arcuate blades `69 are curved in the opposite direction. By a proper choice of the ty-pe of vane member to be used the air may lbe thrown into the shaft of the cupola at a desired angle or from adesired direction, one vane member tending to pass'the air in an upward direction and another vane member tending to pass the air .in a downward direction. Figure 15 shows a vane member somewhat similar to the preferred ,ty-pe shown in Figures 9, 10 and 11 but in which the vaneblades l1 are angularly disposed as illustrated.

Figures 16 te ia--iuclusive illustrate 'anotherarraxigement bf parts which may be utilized for carrying out my invention.- In this arrangement bootleg pipes 19 are provided betweenv the wind fbox 22 and the six tuyres rather than the wind box communicating directly with the tuyres.

As there are six jtuyres'in the illustratory cupola lshown there are six bootleg pipes 10, each communicating with a respective tuyre. i A vane long arm or lever 1l is `rigidly secured to the of the extended'pivot` pin 12. end

By raising the lever 1l to a-horizontai the vane member 12 is sw'ung up within the pipe 19 upon the pivot pins 12."5The upper position lof a vane meaberxwithin a bootleg pipe is shown positionv v in broken lines may be flexibly met A in Figure 17.- By lowering the lever 1l to a ve ical position the vane member 1I is swung vdown pins 12. The lower position of 'a vane member .pipe is shown in full lines in Figure 17. Astop or check 1 5 on the outside of in the pipe 10 upon the pivot' the pipe .10 limits the inward movement of the lever 14 and prevents the vane member 1| from being jammed into the entrance to the tuyre. Reference characters 16 and 11 denote a lock ,arrangement for holding the lever 14, and vane member 1| in raised position as desired.

Peep holes protected by mica peep hole covers 18 are positioned in each bootleg pipe` 10 in such member to its upper position. 'I'he bootleg pipes 10 are rectangular in cross-section to accommodate the vane member 1| movement in the pipe. In eredposition, the vane member 1l yieldably resists the flow of air through the bootleg pipe and through the tuyre. By yielding the flow of air the vane member or controls the flow of air through the tuyre into the shaft of the cupola. By modifying the flow of air into each tuyre the plurality of tuyres may been previously described.

The bootleg pipes 10 are, in effect, extensions` or continuations, of the respective tuyres. 'I'he bootleg pipe may therefore be considered as a part of the tuyre or separate feeding conduit .providing air-from the wind box to the interior of the cupola. In.` this view, the raising'and lowering o1' the `vane member 1i in the bootleg pipe 10 is similar to moving the vane member forward and backward in the tuyre in thev manner described in connection with Figures 9 to 12, inclusive. Similarly, desirable results may -be obtained by changing the position of the vane members 1| from one position toV another to meet requirements and conditions of operation.

It is to be understood that any of the several diierent forms qi vane members disclosed may. be substituted for the other vane members shown mounted in position in different arrangements of my apparatus, as may be desired or required. vlily the method and apparatus here described, desired results in furnace operation are obtainable.. and varying conditions and requirements and answered.

air blast through the *n be controlled, as has munication with said each of the tuyres and to permit t tioned, respectively,

' Although I have described my invention with a certain degree of particularity, it is understood tha`t the present disclosure has been made only by way of example and that numerous changes in the details 'of construction and the combination and `arrangement vof parts may be resorted to without departing from the spirit and the scope of the invention as hereinafter claimed. I claim as my invention:

4- 1. In a furnace having a wind box for supplying a blastof air `to a plurality of tuyres, said vwind box having an inlet adapted to communicate with a source. of air blast and having outlets` in communicationwith said tuyres, a plurality of yieldable resistors positioned at each of said outlets, respectively. to` control the flow of air therethrough, each of said resistors yieldably resisting the air blast through a respective outair out of the outlets through the plurality of ltuyres into the furnace.

plurality of movable resisting members positioned at each of said outlets, respectively, to control the ilow of air therethrough, and retarding means connected to said, resisting members for retard- 3. In a furnace having a wind box for supplying air to a plurality of tuyres, said wind box having an inlet adapted to communicate with a source of an air blast and having outlets in comtuyres, a plurality of movable resisting members disposed at saidoutlets, respectively, in the path of the ilow of air into the respective tuyres, yielding meansl connected to said resisting members for` yieldably urging said resisting members to resist the flow of air into ve ilow of air through the tuyres at modified velocities, and adjustable means for adjustably fixing the yieldability of said yielding means to adjust the modification of said air flow.

4. In a furnace having a wind box for supplyingy a blast of air to a plurality of tuyres, -said Wind box having aninlet adapted to communicate with a source ofanair blast and having outlets in plurality of movable resisting members posito substantially block the flow of air out of each of said outlets through the tuyres,'yielding means for urging said resisting members to yield to tne force thereof to allow'the blast to ilowthrough the tuyres, and adjustable means for adjusting the movability of said resisting members relative to each other in yieldance to said blast, the relative velocities of the air blast tarding the revolving of said vanes, the said vanes modifying the velocities of the air blast flowing through the plurality of tuyres' into the furnace.

6. In a furnace having a plurality of tuyres i supplied with an air blast from a common source,

positioned at each turelative to each the vane memother, the retarded movement of modifying the relative vebers by the air blast locities of the air 7. In a furnace having a windbox for supplyng an air blast to a plurality of tuyres entercommunication with said tuyres, a

resist the said blast and tol blast through the tuyres.J

, ing the furnace,

path of the flow of 'sistors to the force means for adjustably retarding means for changing the flow of the air a squirrel-cage vane member reeach of the tuyres in the air therethrough to be revolved thereby and to modify the rate of flow through the respective tuyre.

8. In a furnace having a common source of an air blast for supplying aplurality of tuyres entering the furnace, a squirrel-cage vane member positioned at each said tuyre, mounting means for said vane members to permit the same to revolve by the force of the air blast through each said tuyre, retarding means for retarding the revolving of said vane members, and adjustable means for adjustably fixing the degree of retardation by said retarding means, the air blast being supplied to the furnace through the plurality of tuyres at modiiied velocities.

9. In a furnace having. a common source of an air blast for supplying a plurality of tuyres entering the furnace; a yieldable resistor positioned in each of said tuyres to yieldably resist and to modify the flow of air therethrough, means forseparately adjusting the yieldance of the reof air blast through the reand means for adjustably moving the position of each resistor in its respective tuyre to vary the modification of the flow of air therethrough. y

10. In a furnace having a windv box for supplying an air blast to a plurality of tuyres entering the furnace, a revolvable vane member positioned in each of said tuyres to modify the flow of air therethrough'mounting means for each said vane member to permit the same to revolve, adjustable means carried by the `mounting the revolving of the vane membersunder the force of the Fair blast, and means connected to said mounting the position of each said vane member in its respective' tuyre.

1l. In a furnace having a wind box for supplying an air blast through a plurality ofA tuyres entering the furnace, a yieldable resistor mounted in each of s aid tuyres to modify the lflow of air therethrough, means for adjusting the yieldanceV of each said resistor to the force of the-air blast volvably mounted at vthrough. the tuyre, and means for adjusting the position of each said resistor in its respective the furnace. tuyres supplied tuyre relative to the interior of 12. In a plurality with an air blast by a members positioned in each tuyre for modifying blast therethrough, and means for separately adjusting the revolvability of-each by the force of theair blast,

whereby the air blast entering the furnace through the plurality of tuyres may be adjustably modified. 13. In a furnace having a plurality of bootleg pipes respectively providing communication between a wind box and a plurality of tuyres entering the furnace, each of the bootleg pipes having a bend peep-hole at the .bend in line with a respective tuyre, the combination of av revolvable vane member positioned in each said bootleg pipe for modifying the flow of air therethrough, bearing means for carrying each said vane member, and lever meansoperable from outside of the bootleg pipe' and connected to each said bearing means vane member in the bootleg pipe out 'of the line of cupola wind box, revolvable vane 'Cil ` peep-hole and tuyre to permit a view therealong.

14. In a system for controlling the flow of air supplied to a furnace from a wind box through a plurality ofv combination of -a yieldable resistor resisting the flow of air therethrough to modify the velocity of the flow and adjusting 'means for each said resistor to adjust the yieldability thereof, whereby the velocity of the flow of air through the plurality of tuyres may be equalized.

15. In the operation of the metallurgical furnace, the method of controlling blast through the plurality of tuyres entering the furnace by .yleldably resisting in'each tuyre the flow of air therethrough and by adjusting the y yieldable resistance in said tuyres to balance the tuyres whereby a unithe plurality of tuyres flow of air through said form flow of air through is obtained.

. 16. In the operation of a metallurgical furnace,

the method of supplying air thereto through a ing within each tuyre the revolvable vane members positioned intermediate its ends and having a around the bend between the balance the modification through the plurality of tuyres,whereby the air plurality of t yres comprising: yieldably resistflow of air therethrough, retarding the now of air by said yieldable resistance, and balancing said retarding to equalize the velocity of the ow of air through the plurality of tuyres.

.117. In a system for supplyingblown airinto a furnace through a plurality of tuyres from a wind box, the combination of first means at each tuyre for modifying the velocity of: the ow of air through the respective tuyres and second means for adjusting each of said first-means to of the flow `of air is supplied to the furnace equalized velocities. Y

18. In a furnace having a wind box for supplying an air blast to a plurality of tuyres entering the furnace, a plurality of movable resisting members positioned at each of said tuyres, respectively, in the pathof the flow o f air through said each tuyre, and means for determinably adjusting the disposition and movability of the respective resisting members at each tuyre to'control the flow of air through said each tuyre.

19. In a furnace having a wind box for supplying an air blast to a plurality of tuyres, said wind box having an inlet adapted a sour-ce of an air blast and having outlets in plurality of at each of said outlets, respectively, to control the. flow of air therethrough, said vane members lbeing yieldably retarded to yieldably resist air, said. vane members having a plurality of vanes extending from an axis, and means for adjustably fixing the disposition of said vanes rela- -tive to the said axis whereby the direction of the flow of airinto the furnace through said tuyres is controlled,`

20. In the operation of ametallurgical furnace, the method of controlling the flow through the plurality of furnace by yieldably resisting through the tuyres and by adjusting the yieldable resistance in said tuyres whereby a conthrough the ltuytres at HERBERT A. Rance.

the flow of air to communicate with 'I the said flow of of air blast tuyres entering the` the flow of air' 

